A Case of Lung Adenocarcinoma with Long-Term Response after Late-Onset Pembrolizumab-Induced Acute Adrenal Insufficiency

Abstract

Pembrolizumab is an anti-programmed cell death protein-1 antibody that is mainly used for the treatment of non-small cell lung cancer (NSCLC). Immune-related adverse events can be caused by immune checkpoint inhibitors; however, few case reports evaluate the prognosis of patients with NSCLC with late-onset immune-related adverse events. In this case, a 63-year-old man with stage IVA lung adenocarcinoma received pembrolizumab as first-line therapy and achieved a complete response. The patient developed hypothyroidism and skin toxicity owing to pembrolizumab over the course of treatment; however, the patient continued with pembrolizumab. The patient discontinued pembrolizumab after 20 cycles owing to appetite loss from 14 months after the initiation of pembrolizumab. Two months later, the symptoms worsened and the patient was taken to hospital by an ambulance owing to movement difficulty. The patient was diagnosed with acute adrenal insufficiency by endocrinological examinations. The condition of the patient improved after hydrocortisone treatment. Sixteen months have passed without the readministration of pembrolizumab and no recurrence of lung adenocarcinoma has been observed. Late-onset, severe, and diverse immune-related adverse events may be a favorable prognostic factor associated with survival.

Keywords: Adrenal insufficiency; Immune-related adverse events; Lung adenocarcinoma; Pembrolizumab; Prognostic factor.

Fig. 1

Chest computed tomography scans. A–C Performed before the initiation of pembrolizumab. D–F Performed on day 196 (after 9 cycles of pembrolizumab) after the initiation of pembrolizumab. A A 2.2-cm tumor in the lower lobe of the left lung was seen (red circle). The primary lesion was observed. B Mediastinal lymph node metastasis was observed. C Left adrenal metastasis was observed. D, E The size of the primary lesion and mediastinal lymph node was reduced. F The left adrenal metastasis had disappeared.

Fig. 2

Clinical course from day 1 to day 5 after admission.

Fig. 3

Chest computed tomography scans. A–C Performed on day 468 after the initiation of pembrolizumab. D–F Performed on day 964 after the initiation of pembrolizumab. There was no recurrence of lung adenocarcinoma, and the patient maintained a complete response.